1. Field of the Invention
The present invention relates to an apparatus for removing a developer remaining between a photoreceptor belt and a squeeze roller in a liquid printer.
2. Description of the Related Art
In general, a liquid printer such as a color laser printer or copier uses a developer, which is a mixture of solid toner of a predetermined color and a liquid carrier serving as a solvent, to develop an electrostatic latent image area formed on a photoreceptor medium such as a photoreceptor belt so that a desired image can be printed. For the above, the liquid printer is provided with a developing unit to develop the developer in the electrostatic latent image area. An example of the developing unit is shown in FIG. 1.
Referring to FIG. 1, a developing unit includes a developing roller 12 and a developer removing apparatus which are installed inside a main body 11. The developing roller 12 is installed to be capable of rotating by means of a driving source (not shown). A development gap G of a predetermined distance between the developing roller 12 and the photoreceptor belt 10 is maintained. The developing roller 12, rotated in the same direction that the photoreceptor belt 10 circulates, develops the developer in an electrostatic latent image area 10a of the photoreceptor belt 10. The developer is supplied by an injection nozzle 17.
The developer removing apparatus includes a first squeeze roller 13 installed adjacent to the developing roller 12, a second squeeze roller 14, a first blade 15, and a second blade 16. During developing, the first squeeze roller 13 squeezes the developer developed in the electrostatic latent image area 10a, while passively being rotated in contact with the photoreceptor belt 10. As a result toner of the developer is made filmy and most of the carriers except for the filmy toner are removed from the electrostatic latent image area 10a.
The second squeeze roller 14, while rotated in contact with the photoreceptor belt 10 in a reverse direction to the direction that the photoreceptor belt 10 circulates, removes the developer remaining on the photoreceptor belt 10 which is wrapped around both end regions of the first squeeze roller 13. The developer flowing along an outer circumferential surface of the second squeeze roller 14 is removed by the second blade 16.
After completion of the developing process, as shown in FIG. 2, a so-called drip-line continues to remain unnecessarily between the photoreceptor belt 10 and the first squeeze roller 13. The "drip-line," which can act as a contamination source in a subsequent developing process, should be removed. To remove the drip line from the photoreceptor belt 10, the circulation speed of the photoreceptor belt 10 is reduced, and the first squeeze roller 13 is reversely rotated in a state in which the first blade 15 is in contact with the first squeeze roller 13. The removed drip-line flows down along the first squeeze roller 13 and is finally removed by the first blade 15 and is dropped into the main body 11.
However, in the above conventional developer removing apparatus, since additional operations are required such as the circulation speed of the photoreceptor belt being reduced and the first squeeze roller being rotated reversely, the operation for removing a drip-line is complicated. Also, since the electrostatic latent image area of the photoreceptor belt is damaged due to friction by the first squeeze roller, the life span of the photoreceptor belt decreases.